Hitachi, Ltd.

Hitachi Consumer Electronics Co., Ltd.

Hitachi-lg Data Storage, Inc.

Renesas Electronics Corporation

Akio Fukushima

Shigeki Inoue

Kazuhiko Ono

Hiroshi Minoda

Eiji Ikeda

Hiroaki Shioyama

Hiroyuki Kimura

Masakazu Ikeda

Koichi Hirose

Motoyuki Suzuki

Koichiro Nishimura

Hiroo Okamoto

Yoshio Miura

Takao Arai

Toshifumi Takeuchi

Takeshi Shimano

Hiroshi Yoshiura

Hiroyuki Tanaka

Yutaka Nagai

Yoshinori Ishikawa

Isao Echizen

Kousuke Anzai

Norihiko Nakano

Masayoshi Okawa

Michihiro Tateishi

Yonemitu Mori

Hajime Ishihara

In a recording medium, an extension address is obtained without changing the number of bits of the address embedded in the wobble. The wobble address is partially or wholly encoded to embed the address information. At the time of reproducing the address information, the original address information is obtained by restoring the embedded information by the decoding process.

Information recording medium, address generation and detection method, and reproducing and recording apparatuses

Optical recording medium capable of increasing the number of wobble address bits and method for recording and reproducing thereof

A configuration for reading out disc management information easily without errors from a disc in which recording is conducted with data recording densities of a plurality of kinds. An optical disc includes a plurality of data recording areas in which information is recorded with data recording densities which are different from each other. Information of the data recording densities in the data recording areas is recorded in a management information recording area (a BCA area or a PIC area) by using a unique format which does not depend upon the data recording densities of the data recording areas. The divided data recording areas are disposed in the same plane of the disc, or disposed over a plurality of recording layers.

Optical disc, optical disc recording apparatus, optical disc reproducing apparatus, information recording method, information reproducing method, and information recording-reproducing method

The present invention enables a comprehensive evaluation from both of data read from a disk and a servo signal of a servo controller. The present invention provides a semiconductor integrated circuit mountable to a disk recording and reproducing drive, which comprises a signal processor of an RF signal read from a pickup, a servo controller responsive to a servo error signal read from the pickup, a memory controller, and an external interface. The memory controller is supplied with read data and a servo signal and stores the read data and the servo signal in a buffer memory according to a time division process. The read data and the servo signal stored in the buffer memory can be transferred to an external device via the external interface by the memory controller.

Semiconductor integrated circuit and disk recording and reproducing drive using the same

Recording capacity per layer is detected from a disc and bit allocation of wobble addresses in a conventional optical disc and bit allocation in a high-density optical disc are controlled selectively to detect physical position addresses on the disc. Address detection can be performed for two kinds of discs which are equal in structure of addresses embedded in wobbles but different in bit allocation of addresses.

Address generating and detecting method and reproducing and recording apparatus

A technique for investigating differences of composition and structural state of a recording layer of an optical disc along with other defects, such as scratches, contamination, warp and distortion, prior to video recording and for setting up appropriate recording conditions in compliance with this result to thereby perform recording is disclosed. In an optical disc recording device capable of recording information on an optical disc, a region to be investigated is defined based on the video recording reservation contents. Then, investigate and evaluate the disc state which can affect the recording quality in a target disc region to be recorded. Next, based on investigation/evaluation results, perform recording setup, recording speed setup, servo control setup and recording position setup to thereby perform the recording. By appropriately modifying the recording setup on a case-by-case basis, it is possible to achieve high-quality recording.

Optical disc recording device

There is a need to accurately lock focus of a laser beam onto a target data layer of a multilayer optical disc. The above need can be addressed by, for example, performing a focus lock operation after a spherical aberration correction amount is set in such a way as to make smaller the ratio of the focus error signal waveform amplitude at the data layer adjacent to a target data layer through which a laser beam passes earlier than through the target data layer to the focus error signal waveform amplitude at the target data layer than that when the spherical aberration correction amount is set so as to be optimal for the target data layer.

Optical disc apparatus therefor

A data reproduction method and apparatus includes first circuitry to produce an information signal from a storage medium. The information signal includes copy control information. Detection circuitry is provided to detect the copy control information. Control circuitry is provided to operate the first circuitry to selectively output the information signal based on the detection result of the detection circuitry.

Method and apparatus for data reproduction

A multilayer optical disc has dimples and/or bumps on a surface of at least one of the layers. Dimensions of the dimples and/or bumps, such as size, frequency and pitch, are selected to generate frequency components in light reflected from the surface that are different from frequency of servo and/or information signals. A disc drive can then use an appropriate filter to remove signals produced by light reflections of an unintended layer.

Optical disc and optical disc apparatus

It is an object of the invention to provide a multi layer optical disc that can be used effectively and an optical disc apparatus that can cope with the multi layer optical disc. The object described above can be accomplished by providing redundancy to the number of layers of the multi layer optical disc. The object can also be accomplished by providing reproducing/recording unit of the multi layer optical disc to the optical disc apparatus.

Multi layer optical disc and optical disc apparatus capable of coping with the multi layer optical disc

The optical disk recording apparatus has the function of correcting the timing shift of the write strategy signal caused by the change in the operating environment of the digital signal processing circuit including the write strategy generating circuit, the laser drive circuit for driving the laser at the time of recording and the flexible printed board for electrical connection between the digital signal processing circuit and the laser drive circuit. Upon determination that the timing shift correction is required, the timing shift is reduced by operating the timing shift correcting function.

Optical disk recording apparatus, laser diode driving apparatus and recording signal generating apparatus

It is an object of the present invention to more strongly protect data to be distributed from being illegally plagiarized, and further, to add an electronic watermark function necessary to protect the copyright to all reproduction means apparatuses. In order to achieve the above-described objects, according to the present invention, data targeted for protection is encrypted, and an encryption key required for decrypting this encrypted data and reproduction control data for protecting the copyright are embedded in encrypted data through the use of the electronic watermark. Thus, when reproducing the data, the electronic watermark is detected, and the encryption key required for decrypting the cryptogram and the reproduction control data for protecting the copyright are restored. Through the use of the restored encryption key, the cryptogram is decrypted. Thus, through the use of the reproduction control data restored, the reproduction of the data targeted for protection is controlled.

Growing community of inventors

Yokohama, Japan

Akio Fukushima